1 Field of the Invention
The present invention relates to a lumbar support device arranged in the seat back of a seat within a car, for example, to support the lumbars of an occupant.
2. Prior Art
The lumbar support device disclosed in preliminarily-opened Japanese Utility Model Disclosure No. 59-2253 is well known as the conventional one which uses particularly the air mat.
An example of this lumbar support device which uses the air mat will be described with reference to FIG. 1. Numeral 1 represents a seat back and the lumbar support device comprises zigzag springs 2 and pads 3 housed in the seat back 1 and three air mats 4 arranged vertically between the zigzag springs 2 and the pads 3. Air is selectively supplied to all, one or two of the three air mats 4 to adjust the position and pressure for supporting the lumbar of an occupant on the seat.
When the position and pressure for supporting the lumbars of the person are adjusted directly by the air mats 4, however, fine adjustment cannot be attained and as the result, the person cannot adjust the position and pressure so satisfactorily as he desires.